Abstract
A new semiautomated instrument is described which quantifies the number of bacteria in potable waters within 3 min, providing a permanent colorimetric record of the results. The bacteria detection device can measure as few as 100 CFU/ml in potable waters. In brief, a 100- to 1,000-ml sample of tap water is drawn through a large surface, customized filter housed in the device, and bacteria, rust, and humic acid in the water are concentrated thereon. A reducing agent is used to remove the rust and humic acid from the filter. The filter is inverted and backflushed to elute the bacteria which are collected and reconcentrated onto a 7-mm-diameter filter surface. The reconcentrated bacteria are stained, and the filter fibers are preferentially decolorized without removing the dye from the bacteria. The color intensity of the filter surface is compared with a color guide to determine the amount of bacteria in the test water.
Full text
PDF
Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Cady P., Dufour S. W., Shaw J., Kraeger S. J. Electrical impedance measurements: rapid method for detecting and monitoring microorganisms. J Clin Microbiol. 1978 Mar;7(3):265–272. doi: 10.1128/jcm.7.3.265-272.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Di Luzio N. R., Friedmann T. J. Letter: Bacterial endotoxins in the environment. Nature. 1973 Jul 6;244(5410):49–51. doi: 10.1038/244049a0. [DOI] [PubMed] [Google Scholar]
- Pezzlo M. T., Wetkowski M. A., Peterson E. M., de la Maza L. M. Evaluation of a two-minute test for urine screening. J Clin Microbiol. 1983 Sep;18(3):697–701. doi: 10.1128/jcm.18.3.697-701.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pfaller M. A., Baum C. A., Niles A. C., Murray P. R. Clinical laboratory evaluation of a urine screening device. J Clin Microbiol. 1983 Sep;18(3):674–679. doi: 10.1128/jcm.18.3.674-679.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Thomason B. M., Wells J. G. Preparation and testing of polyvalent conjugates for fluorescent-antibody detection of salmonellae. Appl Microbiol. 1971 Nov;22(5):876–884. doi: 10.1128/am.22.5.876-884.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wallis C., Melnick J. L., Longoria C. J. Colorimetric method for rapid determination of bacteriuria. J Clin Microbiol. 1981 Sep;14(3):342–346. doi: 10.1128/jcm.14.3.342-346.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]